There are a number of different types of window vent stops available on the market. These window vent stops are used to restrict the opening of windows and doors. For example, a window may be opened only a portion due to security concerns or to increase comfort in the room. Window vent stops are primarily used on double hung windows and sliding doors where a sash or a door member slides from a first position to a second position. The window sash lock prevents the sash or the sliding door from moving past a selected point. These sash locks can permit the window to be opened a desired amount for ventilation or other purposes.
There are many different types of windows currently available. These windows include casement windows, transom windows, single hung windows, double hung windows, sliding windows, etc. Double hung windows are windows that have a pair of window sashes that may be raised and lowered. Each sash resides in a pair of tracks or recesses that are typically at each side edge of the window. This permits the lower sash to be raised and the upper sash to be lowered. Traditionally, most windows were made of wood. More recently, the windows including the window sashes have been made of extruded metal or plastic.
Single hung windows are similar in design to double hung windows except that there is only one sash that may be raised or lowered. Sliding windows are also not unlike double hung windows in design. While a double hung window has sashes that are raised and lowered, a sliding window has sashes that are movable along a track to the right or left. Similarly, sliding doors operate the same way as sliding windows.
Double hung windows, single hung windows, sliding windows and sliding doors have a variety of open positions in which they may be placed. While a fully opened position can be desirable for ventilation purposes there can be a downside to the fully opened position. One downside is security. A fully open window or door, however, can be a location for unauthorized ingress and egress from the premises. For example, a double hung window that is opened wide can be a source of danger to small children who may climb up to the window. As a result, many municipalities have enacted laws requiring window guards. Additionally, an opened window or door can provide an invitation to third parties to gain access to the building. As a result, there are a number of vent stops that are available to secure a window or door having sliding members in a partially opened position. One such stop is shown in U.S. Pat. No. 5,248,174 owned by Ashland Products. Another sash stop is shown in U.S. Pat. No. 4,923,230 owned by Ro Mai. In each of these sash stops there is a spring biased tumbler or dog that pivots from an unlocked position to a locked position as desired. These sash locks are positioned in the frame of the upper sash and when the tumbler is pivoted outwardly the position of the tumbler prevents the lower sash from being raised above a preselected position. Other prior art patents for similar products are U.S. Pat. Nos. 5,553,903 and 5,806,900 both of which are owned by Ashland.
The typical prior art sash lock operates by a tumbler that is activated by pushing downwardly on the tumbler. The tumbler in the prior art sash locks has a catch portion that contacts the underside of the sash lock housing in a closed position. When the sash lock is intended to be activated, the tumbler is moved in a transverse direction opposite the location of the catch portion to release the catch from the housing. The spring in the sash lock causes the tumbler to be raised into an activated position to lock the sash or door in position.
One of the problems in the operation of the prior art sash locks is that it is frequently difficult for the user to move the tumbler away from the housing to release the tumbler from its recessed position. This is particularly true where the spring that causes the tumbler to be raised is new and/or relatively strong. Many times, the user finds it difficult to maneuver the tumbler away from the housing to release the tumbler. Although many tumblers are provided with surfaces that increase the user's ability to move the tumbler, these surfaces are frequently insufficient to overcome the difficulties of the prior art vent locks.
Similarly, the prior art sash locks can also be difficult to operate when the user wants to release the window or door for travel. The user must not only push down on the tumbler to release the sash but also must shift the tumbler so that it catches the catch portion of the housing. If the catch portion of the housing is not contacted by the tumbler, the tumbler will be raised due to the pressure of the spring and the sash will not be permitted to move.
While the vent stops of the prior art are generally satisfactory in operation there is also a need for improved vent stops. The problems of the prior art stops are solved by the vent stop of the present invention which operates in a unique manner compared to the traditional sash locks.